1. Field of the Invention
The present invention is directed to a cleaning fan for a cleaning system of a combine having two outlets. The first outlet provides a primary and secondary air blast to grain and chaff falling to a step pan from the threshing system and to grain and chaff falling from the step shoe and separating system to a conditioning pan. The second outlet provides a chaffer air blast to the chaffer of the cleaning shoe.
2. Description of the Prior Art
Agricultural combines are large machines that harvest, thresh, separate and clean an agricultural crop. The resulting clean grain is stored in a grain tank located on the combine. The clean grain can then be transported from the grain tank to a truck, grain cart or other receiving bin by an unloading auger.
After separation and threshing the grain is directed to a cleaning system for separating chaff from the clean grain. Traditionally the cleaning systems of combines comprise a cleaning shoe having a chaffer and sieve. The chaffer and sieve are reciprocated fore and aft. A cleaning fan directs aspirated air through the chaffer and sieve blowing the lighter chaff out the rear of the combine. The heavier clean grain falls through the chaffer and sieve and is collected by a clean grain auger that directs it to a clean grain elevator. The elevator transports the clean grain to a clean grain tank on the combine.
Cleaning fans having two outlets providing two distinct air blasts are well known, see U.S. Pat. Nos. 4,531,528 and 4,821,744.